scholarly journals Oxygen Consumption by Anaerobic Saccharomyces cerevisiae under Enological Conditions: Effect on Fermentation Kinetics

2003 ◽  
Vol 69 (1) ◽  
pp. 113-121 ◽  
Author(s):  
Eric Rosenfeld ◽  
Bertrand Beauvoit ◽  
Bruno Blondin ◽  
Jean-Michel Salmon
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Oxygen Consumption ◽  
Stationary Phase ◽  
Respiratory Chain ◽  
Unsaturated Fatty Acids ◽  
De Novo ◽  
Anaerobic Growth ◽  
Fermentation Rate ◽  
Fermentation Kinetics ◽  
Oxygen Pulse

ABSTRACT The anaerobic growth of the yeast Saccharomyces cerevisiae normally requires the addition of molecular oxygen, which is used to synthesize sterols and unsaturated fatty acids (UFAs). A single oxygen pulse can stimulate enological fermentation, but the biochemical pathways involved in this phenomenon remain to be elucidated. We showed that the addition of oxygen (0.3 to 1.5 mg/g [dry mass] of yeast) to a lipid-depleted medium mainly resulted in the synthesis of the sterols and UFAs required for cell growth. However, the addition of oxygen during the stationary phase in a medium containing excess ergosterol and oleic acid increased the specific fermentation rate, increased cell viability, and shortened the fermentation period. Neither the respiratory chain nor de novo protein synthesis was required for these medium- and long-term effects. As de novo lipid synthesis may be involved in ethanol tolerance, we studied the effect of oxygen addition on sterol and UFA auxotrophs (erg1 and ole1 mutants, respectively). Both mutants exhibited normal anaerobic fermentation kinetics. However, only the ole1 mutant strain responded to the oxygen pulse during the stationary phase, suggesting that de novo sterol synthesis is required for the oxygen-induced increase of the specific fermentation rate. In conclusion, the sterol pathway appears to contribute significantly to the oxygen consumption capacities of cells under anaerobic conditions. Nevertheless, we demonstrated the existence of alternative oxygen consumption pathways that are neither linked to the respiratory chain nor linked to heme, sterol, or UFA synthesis. These pathways dissipate the oxygen added during the stationary phase, without affecting the fermentation kinetics.

scholarly journals Optimizing anaerobic growth rate and fermentation kinetics in Saccharomyces cerevisiae strains expressing Calvin-cycle enzymes for improved ethanol yield

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Ioannis Papapetridis ◽  
Maaike Goudriaan ◽  
María Vázquez Vitali ◽  
Nikita A. de Keijzer ◽  
Marcel van den Broek ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Growth Rate ◽  
Ethanol Yield ◽  
Calvin Cycle ◽  
Anaerobic Growth ◽  
Fermentation Kinetics ◽  
Calvin Cycle Enzymes

scholarly journals Anaerobic growth of Saccharomyces cerevisiae CEN.PK113-7D does not depend on synthesis or supplementation of unsaturated fatty acids

2019 ◽  
Vol 19 (6) ◽  
Author(s):  
Wijb J C Dekker ◽  
Sanne J Wiersma ◽  
Jonna Bouwknegt ◽  
Christiaan Mooiman ◽  
Jack T Pronk
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Unsaturated Fatty Acids ◽  
Saturated Fatty Acids ◽  
Laboratory Strain ◽  
Tween 80 ◽  
Batch Cultivation ◽  
Anaerobic Growth ◽  
Growth Media ◽  
Yeast Viability

ABSTRACT In Saccharomyces cerevisiae, acyl-coenzyme A desaturation by Ole1 requires molecular oxygen. Tween 80, a poly-ethoxylated sorbitan-oleate ester, is therefore routinely included in anaerobic growth media as a source of unsaturated fatty acids (UFAs). During optimization of protocols for anaerobic bioreactor cultivation of this yeast, we consistently observed growth of the laboratory strain S. cerevisiae CEN.PK113-7D in media that contained the anaerobic growth factor ergosterol, but lacked UFAs. To minimize oxygen contamination, additional experiments were performed in an anaerobic chamber. After anaerobic precultivation without ergosterol and Tween 80, strain CEN.PK113-7D and a congenic ole1Δ strain both grew during three consecutive batch-cultivation cycles on medium that contained ergosterol, but not Tween 80. During these three cycles, no UFAs were detected in biomass of cultures grown without Tween 80, while contents of C10 to C14 saturated fatty acids were higher than in biomass from Tween 80-supplemented cultures. In contrast to its UFA-independent anaerobic growth, aerobic growth of the ole1Δ strain strictly depended on Tween 80 supplementation. This study shows that the requirement of anaerobic cultures of S. cerevisiae for UFA supplementation is not absolute and provides a basis for further research on the effects of lipid composition on yeast viability and robustness.

Induction of repressible acid phosphatase by unsaturated fatty acid in Saccharomyces cerevisiae

1989 ◽  
Vol 94 (3) ◽  
pp. 511-516
Author(s):  
S. Doi ◽  
M. Watanabe ◽  
K. Tanabe ◽  
M. Nakasako ◽  
M. Yoshimura
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Acid Phosphatase ◽  
Linolenic Acid ◽  
Unsaturated Fatty Acids ◽  
De Novo ◽  
Intracellular Level ◽  
High Concentration ◽  
Arachidonic Acids ◽  
De Novo Protein Synthesis

We studied the induction of acid phosphatase (APase) by fatty acids in Saccharomyces cerevisiae. S. cerevisiae has two types of APase: constitutive and repressible enzymes. The synthesis of the latter APase is normally derepressed by depletion of inorganic phosphate (Pi) in the incubation medium. Of the saturated and unsaturated fatty acids tested, linoleic, linolenic and arachidonic acids induced the synthesis of APase even in the presence of a high concentration of Pi, whereas palmitic, stearic and oleic acids did not. De novo protein synthesis but not stimulation of secretion of the enzyme was required for the induction. Genetic analyses using plasmids carrying the genes, PHO5 and PHO3, that code for repressible APase and constitutive APase, respectively, showed that linolenic acid induced the formation of repressible APase. Linolenic acid inhibited the uptake of exogenous 32Pi and simultaneously lowered the intracellular level of Pi. These circumstances indicate that linolenic acid-induced derepression of repressible APase is primarily caused by a fall in the intracellular level of Pi. However, cells that had been preincubated in the presence of a high concentration of Pi produced APase shortly after the addition of linolenic acid. It is, therefore, suggested that, as well as a normal regulatory mechanism for derepression of repressible APase, a mechanism independent of the external level of Pi participates in the induction of repressible APase by linolenic acid.

Quantitative Effects of Unsaturated Fatty Acids in Microbial Mutants. IV. Lipid Composition of Saccharomyces cerevisiae When Growth is Limited by Unsaturated Fatty Acid Supply

1975 ◽  
Vol 53 (12) ◽  
pp. 1262-1277 ◽  
Author(s):  
Bruce J. Holub ◽  
William E. M. Lands
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acids ◽  
Fatty Acid ◽  
Stationary Phase ◽  
Unsaturated Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Total Phospholipid ◽  
Phospholipid Content ◽  
Membrane Phospholipids ◽  
Mole Percentage

The Saccharomyces cerevisiae mutant KD46 (ole 2), which is unable to synthesize unsaturated fatty acids, was grown on limiting amounts of different added unsaturated fatty acids. The acyl chain composition of the cellular lipid classes was determined in these cultures at different stages of growth. During growth on added oleic acid, there was no marked change in the mole percentage of phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, or phosphatidylserine among the total phospholipids.Cells grown on palmitoleic, oleic, or linoleic acid showed a steady decrease in their total phospholipid levels per cell concomitant with a decrease in growth rate approaching minimal levels at stationary phase. Furthermore, the mole percentage of the supplemented unsaturated fatty acid in the cellular phospholipids also decreased during growth and attained minimal values when growth ceased.At stationary phase the total phospholipid content per cell was similar for cells grown on a wide range of fatty acids or mixtures thereof, whereas the composition of the fatty acids in the cellular phospholipids were strikingly different. The differences in efficiencies for supporting growth of most of the unsaturated fatty acids tested did not seem due to the extent of their incorporation into cellular phospholipids, but rather to differences in the ability of the derived membrane phospholipids to support cellular functions.Palmitoleate, oleate, linoleate, linolenate, arachidonate, eicosapentaenoate, and docosahexaenoate all appeared to contribute to the functionality of cellular membranes in an additive linear manner. Thus, the contribution of these acids to cellular growth can be characterized by a functionality factor that seems independent of the mixtures of acids supporting growth. Use of the functionality concept allows the cumulative influence of many different acids to be summarized quantitatively by a single number rather than resorting to qualitative descriptions of the degree of unsaturation or 'fitness' of the membrane phospholipids.

scholarly journals Forever panting and forever growing: physiology of Saccharomyces cerevisiae at extremely low oxygen availability in the absence of ergosterol and unsaturated fatty acids

2019 ◽  
Vol 19 (6) ◽  
Author(s):  
Bruno Labate Vale da Costa ◽  
Vijayendran Raghavendran ◽  
Luís Fernando Mercier Franco ◽  
Adriano de Britto Chaves Filho ◽  
Marcos Yukio Yoshinaga ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acid ◽  
Unsaturated Fatty Acids ◽  
Laboratory Strain ◽  
Glucose Consumption ◽  
Continuous Cultivation ◽  
Low Ph ◽  
Anaerobic Growth ◽  
Low Oxygen ◽  
Lipid Fatty Acid

ABSTRACT We sought to investigate how far the growth of Saccharomyces cerevisiae under full anaerobiosis is dependent on the widely used anaerobic growth factors (AGF) ergosterol and oleic acid. A continuous cultivation setup was employed and, even forcing ultrapure N2 gas through an O2 trap upstream of the bioreactor, neither cells from S. cerevisiae CEN.PK113–7D (a lab strain) nor from PE-2 (an industrial strain) washed out after an aerobic-to-anaerobic switch in the absence of AGF. S. cerevisiae PE-2 seemed to cope better than the laboratory strain with this extremely low O2 availability, since it presented higher biomass yield, lower specific rates of glucose consumption and CO2 formation, and higher survival at low pH. Lipid (fatty acid and sterol) composition dramatically altered when cells were grown anaerobically without AGF: saturated fatty acid, squalene and lanosterol contents increased, when compared to either cells grown aerobically or anaerobically with AGF. We concluded that these lipid alterations negatively affect cell viability during exposure to low pH or high ethanol titers.

Dynamic regulation of mitochondrial respiratory chain efficiency in Saccharomyces cerevisiae

Microbiology ◽  
2011 ◽  
Vol 157 (12) ◽  
pp. 3500-3511 ◽  
Author(s):  
Jarne Postmus ◽  
Işil Tuzun ◽  
Martijn Bekker ◽  
Wally H. Müller ◽  
M. Joost Teixeira de Mattos ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Oxygen Consumption ◽  
Respiratory Chain ◽  
Proton Translocation ◽  
Carbon Sources ◽  
Mitochondrial Respiratory Chain ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Dynamic Regulation

To adapt to changes in the environment, cells have to dynamically alter their phenotype in response to, for instance, temperature and oxygen availability. Interestingly, mitochondrial function in Saccharomyces cerevisiae is inherently temperature sensitive; above 37 °C, yeast cells cannot grow on respiratory carbon sources. To investigate this phenomenon, we studied the effect of cultivation temperature on the efficiency (production of ATP per atom of oxygen consumed, or P/O) of the yeast respiratory chain in glucose-limited chemostats. We determined that even though the specific oxygen consumption rate did not change with temperature, oxygen consumption no longer contributed to mitochondrial ATP generation at temperatures higher than 37 °C. Remarkably, between 30 and 37 °C, we observed a linear increase in respiratory efficiency with growth temperature, up to a P/O of 1.4, close to the theoretical maximum that can be reached in vivo. The temperature-dependent increase in efficiency required the presence of the mitochondrial glycerol-3-phosphate dehydrogenase GUT2. Respiratory chain efficiency was also altered in response to changes in oxygen availibility. Our data show that, even in the absence of alternative oxidases or uncoupling proteins, yeast has retained the ability to dynamically regulate the efficiency of coupling of oxygen consumption to proton translocation in the respiratory chain in response to changes in the environment.

scholarly journals Regulatory Mechanisms Controlling Expression of the DAN/TIR Mannoprotein Genes During Anaerobic Remodeling of the Cell Wall in Saccharomyces cerevisiae

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1169-1177
Author(s):  
Natalia E Abramova ◽  
Brian D Cohen ◽  
Odeniel Sertil ◽  
Rachna Kapoor ◽  
Kelvin J A Davies ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Consensus Sequence ◽  
Ectopic Expression ◽  
Constitutive Expression ◽  
Anaerobic Growth ◽  
Zinc Cluster ◽  
Sterol Transport ◽  
Genes Encoding ◽  
Altered Regulation ◽  
Repression Domain

Abstract The DAN/TIR genes of Saccharomyces cerevisiae encode homologous mannoproteins, some of which are essential for anaerobic growth. Expression of these genes is induced during anaerobiosis and in some cases during cold shock. We show that several heme-responsive mechanisms combine to regulate DAN/TIR gene expression. The first mechanism employs two repression factors, Mox1 and Mox2, and an activation factor, Mox4 (for mannoprotein regulation by oxygen). The genes encoding these proteins were identified by selecting for recessive mutants with altered regulation of a dan1::ura3 fusion. MOX4 is identical to UPC2, encoding a binucleate zinc cluster protein controlling expression of an anaerobic sterol transport system. Mox4/Upc2 is required for expression of all the DAN/TIR genes. It appears to act through a consensus sequence termed the AR1 site, as does Mox2. The noninducible mox4Δ allele was epistatic to the constitutive mox1 and mox2 mutations, suggesting that Mox1 and Mox2 modulate activation by Mox4 in a heme-dependent fashion. Mutations in a putative repression domain in Mox4 caused constitutive expression of the DAN/TIR genes, indicating a role for this domain in heme repression. MOX4 expression is induced both in anaerobic and cold-shocked cells, so heme may also regulate DAN/TIR expression through inhibition of expression of MOX4. Indeed, ectopic expression of MOX4 in aerobic cells resulted in partially constitutive expression of DAN1. Heme also regulates expression of some of the DAN/TIR genes through the Rox7 repressor, which also controls expression of the hypoxic gene ANB1. In addition Rox1, another heme-responsive repressor, and the global repressors Tup1 and Ssn6 are also required for full aerobic repression of these genes.

scholarly journals Analysis of thepdx-1(snz-1/sno-1) Region of theNeurospora crassaGenome: Correlation of Pyridoxine-Requiring Phenotypes With Mutations in Two Structural Genes

Genetics ◽  
2001 ◽  
Vol 157 (3) ◽  
pp. 1067-1075 ◽  
Author(s):  
Laura E Bean ◽  
William H Dvorachek ◽  
Edward L Braun ◽  
Allison Errett ◽  
Gregory S Saenz ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Stationary Phase ◽  
Neurospora Crassa ◽  
Vitamin B6 ◽  
Structural Genes ◽  
Protein Coding ◽  
Previous Conclusion ◽  
Protein Coding Genes ◽  
Shared Function ◽  
High Gene

AbstractWe report the analysis of a 36-kbp region of the Neurospora crassa genome, which contains homologs of two closely linked stationary phase genes, SNZ1 and SNO1, from Saccharomyces cerevisiae. Homologs of SNZ1 encode extremely highly conserved proteins that have been implicated in pyridoxine (vitamin B6) metabolism in the filamentous fungi Cercospora nicotianae and in Aspergillus nidulans. In N. crassa, SNZ and SNO homologs map to the region occupied by pdx-1 (pyridoxine requiring), a gene that has been known for several decades, but which was not sequenced previously. In this study, pyridoxine-requiring mutants of N. crassa were found to possess mutations that disrupt conserved regions in either the SNZ or SNO homolog. Previously, nearly all of these mutants were classified as pdx-1. However, one mutant with a disrupted SNO homolog was at one time designated pdx-2. It now appears appropriate to reserve the pdx-1 designation for the N. crassa SNZ homolog and pdx-2 for the SNO homolog. We further report annotation of the entire 36,030-bp region, which contains at least 12 protein coding genes, supporting a previous conclusion of high gene densities (12,000-13,000 total genes) for N. crassa. Among genes in this region other than SNZ and SNO homologs, there was no evidence of shared function. Four of the genes in this region appear to have been lost from the S. cerevisiae lineage.

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